Flat warp knitting machine



June 20, 1961 A. w. H. PORTER FLAT WARP KNITTING MACHINE 6 Sheets-Sheet1 Filed March 28, 1960 Inventor A W H Porter y I I Mttorneys June 20,1961 A. w. H. PORTER FLAT WARP KNITTING MACHINE 6 Sheets-Sheet 2 FiledMarch 28. 1960 Inventor ,4. W/7. porfer' By Mtomeys June 20, 1961 FiledMarch 28, 1960 A. w. H. PORTER 2,988,906

FLAT WARP KNITTING MACHINE 6 Sheets-Sheet 3 5 5 5 2/ 2 55 -51 ii1 6/ 2624 22 50 57 60g 25 Q 55 6 Q a? i 40 f 29 6 55 ',.g 3/3237 53 5f -2 2'725 /'7 /5 4/ 754 Inventor AIM/ Pan er June 20, 1961 A. w. H. PORTER2,988,906

FLAT WARP KNITTING MACHINE Filed March 28, 1960 6 Sheets-Sheet 4Inventor A. W. H. Porier' Attorneys June 20, 1961 A. w. H. PORTER2,988,906

FLAT WARP KNITTING MACHINE Filed March 28, 1960 6 Sheets-Sheet 5Inventor Attorneys June 20, 1961 A. w. H. PORTER 2,988,906

FLAT WARP KNITTING MACHINE Filed March 28, l960 6 Sheets-Sheet 6Inventor A. W H. Parfer Attorneys FLAT WARP KNITTING MACHINE WilliamHenry Porter, Bnrton-on-Trent, England,

assignor to Hb'ourn-F.N.-F. Limited Filed Mar. 28, 1960, Ser. No. 18,039

Allan priority, application Great Britain Apr. 14, 1959 7 Claims. 01.66-86) In flatwarp knitting machines having a row of reciprocatinghooked needles and one or more rows of guides which are swungto and froacross the row of needles I, for laying the warpthreads in the hooks ofthe needles, "it isdesirable (for the needles to perform a movementwhich. includes a dwell when. the needles are at that end of-theirstroke at which. the threads are laid into their .h'ooks." The needlescannot usually be motionless during 'thisdwell, but their speed shouldbe considerably less "than that in the remainder of the stroke.

Such a .dwell is very advantageous in that it helps jto ensure that thethreads are accurately laid in the .needle hooks before the needle hooksare closed. The

greater the number of guide bars which the machine l1;as,. that,isthegreater the number of rows of guide eyes, Lthe more necessary a dwellbecomes to ensure ithatjthere is sufiicient time for the threads leadingfrom all'the different rows offguide eyes to be ,laid in the needlehooks.

It is also essential that the guide eyes should remain ample, three ormore guide bars, the period during {yvhichthe guides remain behind theneedles must be considerable becausethe outermost row of guide eyes=must move sufliciently far to enable the innermost row nearest to theneedles to perform its shogging movefn'ent before "this"row moves backagain.

*According to the present invention a flat warp knitting machine with arowof reciprocating hooked needles carried on a needle bar, and one ormore pivotally mounted guide'bars which are swung'to and fro across therow of needles, has its needle bar driven from a "paifio feccentrics,which operate in parallel and one of -whichis rotated at twice the speedof the other, through two connecting rods connecting the eccentrics to acrosshead, and through a mechanism which includes a member connected tothe cross-head in a position between the connections tothe cross-head ofthe two connecting rods and the guide bar or bars are driven from thesanie "pair of'ecoentrics through the connecting rods and the cross-headand through a further mechanism which includes a second member connectedto the cross-"head in a position on the side of the connection to thecrosshead of the connecting rod of the slower eccentric re- 'm'otefromthe connecting rod of the faster eccentric.

Preferably the distance between the 'centres of the connections of thefirst m ember and of the connecting rod of the faster eccentric to thecross-head and the distance between the centres of the connections ofthe first member and of the connecting rod of the "slower eccentric tothe cross-head are in the ratio of substantially 2:1. Further, thedistance between 'the'centres 'of the connections o f the first memberand of the connecting rod -of the"'slower eccentric and the distancebetween the centres of the connections of the second member and nf-theconnecting rod of the slower eccentric, are substantially equal to eachother.

,Un wd St s P t n .0

Patented June20, 1961 2 and some of their associated mechanism is usedto drive both the needles and the guides, saves many Working parts inthe knitting machine, thus making the machine more compact and cheaperto manufacture. This is an obvious advantage.

The arrangement also has the furtherand more important advantage that itproduces particularly satisfactory movements of the needles and of theguides. The curve of movement of the needles plotted against a base ofthe angle of rotation of the slower eccentric, which revolves once ineach knitting cycle, has a very flat peak extending on both sides of the180 degree point of the cycle of movement. The curve of movement of theguides, on the other hand, approximates to an inverse of the movement ofthe needles and is 180 degrees out of phase with the curve of movementof the needles.

dwell, it is only necessary. for the innermost .rowof guides, that isthe row nearest the row of needles, 'to be 'just behind the row ofneedles when the shogging movements are -made.' The dwell in the guidemovement completely obviatm the necessity, whic'h'would occur if 'theguides made a simple harmonic movement, for the guides to swing farbeyond the backs of the row of needles to enable the innermost row ofguides to be clear of the row of needles for long enough to enable it tomake its shogging movement.

If the guides made a simple harmonic motion in this way, the outermostrow of guides in a multi-bar machine would have to swing a verysubstantial distance away from the row of needles. The threads wouldtherefore,

be drawn by the guides away from the shanks of the needles and thiswould cause the helices of thread wrapped around the shanks of theneedles by the guides to be drawn down the-shanks of the needles. Thisis most unsatisfactory and tends to cause mislapping of the threads inthe hooksof the needles. 7

With the driving mechanism in accordance with the present invention,howeverg as already-explained, the

'- guides do not need to move far beyond the backs of the knittingelements themselves removed to show the .-'Il1is"ar-rangement, bywhichithe same pair of eccentrics I the needles and any tendency to dropstitches or mislap due to drawing of the'thread helices down the shanksof the needles is greatly reduced.

An example of a flat warp knitting machine constructed 'in accordancewith the present invention is illustrated in the accompanying drawings,in which:

FIGURE 1 is a front elevation of the machine with general structure moreclearly; FIGURE 2 is an'end elevation of the machine complete with theknitting elements; I a v FIGURE 3 is a cross-section to a larger scalethrough the part of the machine showing the driving-mechanism of theneedles and guidebars; 7

FIGURE 4 is a cross-section similar to that shown in FIGURE 3, butshowing the driving mechanism of reciprocating tongues which open andclose the hooks of the needles; v 5

FIGURE 5 is a cross-section also similar to FIGURE 3, but showing thedriving mechanism of sinkers;

FIGURE 6 is a timing'diagram showing the of the needles during oneknittingcycle; v 1,; FIGURE 7 is a similar diagram, but showing themomotion ,tion of the guide eyes;

FIGURE 8 is another diagram, similar to FIGURE 7, but showing a modifiedmovement of the guide eyes; and

FIGURE 9 is a further diagram to a larger scale than FIGURES 6 to. 8showing the movement of the needles relatively to the guides when theneedles perform the movement shown in FIGURE 6 and the guides performthe movement shown in either FIGURE 7 or FIGURE .8.

The knitting machine shown in the drawings is of the kind in which thehookedknitting needles have tubular .shanks in which rod-like tonguesare independently re- ;eiprocated upwards and downwards relatively tothe needles to open and close the needle hooks. The invention is,however, equally applicable to flat warp knitting machines of othertypes. For example, those having bearded needles, latched needles orneedles with tongues zlQ fltedin a groove in the needle shank.

.-A s shown in FIGURES l and 2, the machine has a ;main frame 1extending over its full width. This frame ,is supported at both ends onlegs 2 and 3 and also'intermediately on a further leg 4. Above the legs3 and 4 the frame 1 has integral upwardly and downwardly extendingsupports 5 and 6 respectively on which sectional warp beams 7 and 8 arerotatably mounted.

The machine is driven in a conventional manner by an electric motor 9mounted on the left-hand end' of the frame 1. This motor rotates thewarp beams 7 and 8 by means of a headstock 10 and a similar headstockadjacent the left-hand end as seen in FIGUREl of the warp beam 8. Theseheadstocks are rotated through a conventional transmission which isnotillustrated.

The motor also rotates sprockets carrying pattern chains within ahousing 11 at the left-hand end of the frame 1. "The pattern chains movebars 12 to and fro from left to right. The bars 12 are connected to the.guide bars of the machine which are not shown in FIGURE 1 of thedrawings, to make these guide bars make shogging and lapping movementsin a direction across the width of the machine. Again the patternmechanism is quite conventional and is not therefore illustrated. Nextthemotor 9 rotates a roller 12a on which the knitted fabric is wound.Finally the motor 9 rotates two main driving shafts 13 and 14 enclosedwithin a sump 15 and extending across the whole width of the machine.The driving shafts are driv- -en by means of toothed gearing within ahousing 16. The driving shafts are connected together by gearing withinthe housing 16 in such a way that the shaft 13 is rotated at twice thespeed of the shaft 14. The shaft 14 makes the same number of revolutionsper minute as the machine makes knitting cycles per minute and the shaft13 runs at twice this speed- The driving shafts 13 and 14 operate theknitting elements (which are not shown in FIGURE 1) through drivingmechanisms illustrated in detail in FIGURES 3 to 5 of the drawings. Oneof each of these mechanisms is contained within each of the casings 17,18, 19 and 20 so that the knitting elements are positively driven atfour different places across the width of the machine. The drivingmechanisms in each of the casings 17 to 20 are the same as each otherand therefore the contents of only one casing 17 is illustrated inFIGURES 3 to 5.

' As shown in FIGURE 3 of the drawings a row of hooked needles 21 havingtubular shanks are fixed in a sectional die-cast block 22 which isclamped to a needle bar 23. The bar '23 extends over the whole knittingwidth of the machine and is carried at four separate points along itslength by a bracket 24 which extends from a U-shaped lever 25. TheU-shaped lever 25 is pivotally mounted by means of a pin 26 on an arm 27which is .itself pivoted on a fixed shaft 28 which is mounted in thecasing 17. A second arm 29 of the U-shaped lever 25 is pivotallyconnected by a pin 30 to a ball crank lever 31. The bell crank lever 31is pivoted on a shaft 32 similar to the shaft 28, and its other arm'33is connected by a pivot pin 34 to a cross-head 35. The left-hand end ofthe cross-head 35 is connected by a pivot pin 36 to a connecting rod 37.The connecting rod 37 has at its lower end a strap 38 which surrounds aneccentric 39 on the driving shaft 13. Towards its right-hand end thecrosshead 35 is pivotally connected by a pin 40 to a second connectingrod 41. The connecting rod 41 has a strap 42 at its lower end whichsurrounds an eccentric 43 on the driving shaft 14; Six rows of guideeyes 44' are mounted on six separate guide bars 45 to 50. The guide bars45 to 50, as already mentioned, are connected by the bars 12 to thepattern mechanism. They are mounted so that they can slide to and froacross the width of the machine, that is along the row of needles 21, ona carrier 51 which is supported by prongs 52 having a backconnectingpiece 53 which is pivotally connected by a'pin 54 to arms 55projecting upwards from the casing 17. The lower end 56 of the carrier51 is pivotally connected by a pin 57 to a push rod 58. The right-handend of the'push rod 58, as seen in FIGURE 3 of the drawings, ispivotally connected by a pin 59 to a bell crank lever 60. The bell cranklever'60 is mounted on a shaft 60a and is connected by an adjustablepivotal joint, which consists of a pin 61 whichpasses through a slot 62,to a further conneetingrod 63. The lower end of the connecting rod 63is. connected by a pin 64 to the right-hand end of the cross-head 35.This end of the cross-head 35 projects beyond the pin 40 by which it isconnected to the connecting rod 41.

The distance between the centres of the pins 36 and 34 is twice thedistance between the centres of the pins 34 and 40 and the distancebetween the pins 40 .an d 64 is substantially equal to the distancebetween the centres of the pins 34 and 40. I I

The eccentrics 39 and '43 have the-same eccentricity aseach other andboth are at their top dead centre'positions at the same instant. Whenthe shaft 13', and with it the eccentric 39, is rotated at twice thespeed of the shaft 14 and the eccentric 43, as already described, theneedles 21 reciprocate in a direction along the lines-of their shanksand perform the movement shown in FIG- URE 6 of the drawings. Thisfigure shows therheight of the needles above their bottom dead centreposition plotted on a base which shows the rotation of the shaft 14 indegrees from a datum position. It will be seen from FIGURE 6 that theneedles move in a direction towards the guide eyes 44 fairly rapidly.They then dwell near their uppermost position with only a very slightdownward movement taking place and they then move rapidly downwardsagain. The guide eyes perform a curve of movement which isvery nearly anexact mirror image of that of the needles, but displaced from it bydegrees. This guide movement is very important and gives verysatisfactory results. Theguide eyes remain in a position at the backs ofthe needles, that is on the closedside of the needle hooks and theleft-hand end of the swing as shown in FIGURE 3 of the drawings. Theythen swing rapidly to the right as shown in FIGURE 3 of the drawings tothe fronts of the needles and back again to the left where they remainalmost stationary for some considerable time until the cycle of movementis repeated. I

,As shown in FIGURE 4 of the drawings a row of tongues 65 which lieinside the tubular shanks of the needles 21 are fixed to a tongue bar66. The tongue bar 66 is supported atfour points along its length .by abracket 67 extending upwards from a U-shaped lever 68 similar to thelever 25 carrying the needles 21. The lever 68 is supported from apivoted arm 69 similar to the arm 27 and this is also pivoted on theshaft 28. Anarm 70 of the lever 68 is pivoted by apin 71 to a bell cranklever 72 similar to the bell crank lever 33. The bell crank lever 72 ispivoted on the shaft 32. The righthand end of the bell crank lever 72 ispivotally connected by a pin 73 to a cross-head 74 which is in'turnconnected by connecting rods 75 and 76 to eccentrics 77 and "78respectively on the shafts 13 .and 14.

"The throws of the eccentrics 77 and 78 and their angular relationshipwith each other are adjusted so that the tongues move relatively to theneedles in such a way that the hooks of the needles close just as, theneedles start to move downwards at the right-hand side of their curve ofmovement shown in FIGURE 6 of the drawings and to a sinker-bar 82 whichis supported at four points along its length on an arm 83 which ispivotally connected by a .pin 84 to a further arm 85 mounted on a fixedshaft 86. The right-hand end of the arm 83, as seen in FIG- URE 5 of thedrawings, has a slot 87 through which a pin 88 passes. The pin 88 isfixed to a lever 89 which is pivoted on the shaft 32. The lever 89 isthe same as the bell crank levers 33 and 72 for production reasons: inthe mechanism for driving the sinkers, however, its left-hand arm 90 isnot used. In the same way, in the mechanisms for driving the needles andthe tongues the opening in which the pin 88 is fixed is also not used.The end of the lever 89 is connected by a pin 91 to a cross-head 92similar to the cross-head 74. The crosshead 92 is in turn connected byconnecting rods 93 and 94 to eccentrics 95 and 96 on the shafts 13 and14. Here again the angular positions of the eccentrics 95 and 96 areadjusted to provide the required sinker movement. This may vary inaccordance with the nature of the fabric being knitted, but is ingeneral similar to that described in United States Patent No. 2,292,287,to Peel and Mor- IlSOll.

For knitting some fabrics it will not be necessary to employ all six ofthe guide bars 45 to 50. In many cases in fact all that will benecessary are two guide bars with their associated rows of guide eyes.Under these circumstances it is not necessary for the guides to have along dwell whilst they are at the backs of the needles to allow theshogging movement of the guide eyes to take place, and it is better,therefore, that the movement shown in FIGURE 8 of the drawings with itslong dwell and its consequent rapid acceleration of the guides should beavoided. When only two guide bars are used a simple harmonic motion ismore satisfactory. The mechanism shown in FIGURE 3 of the drawings canvery easily be adapted to take care of this eventuality. All that isnecessary is for the rod 63 to be provided with an extension 97 shown indotted lines in FIGURE 3 of the drawings and also the connecting rod 41must be provided with an additional bush 98. To change the motion of theguides over from that shown in FIGURE 8 of the drawings to a simpleharmonic motion shown in FIGURE 7 of the drawings, the pin 64 is removedfrom the position in which it is shown in FIGURE 3 and is insertedinstead through the bush 98 and through a corresponding bush in theextension 97 on the rod 63. In this way the bell crank lever 60, and theremainder of the mechanism for oscillating the guide bars, is connectedonly to the eccentric 43. The eccentric 39 has no further effect. Theguide thus performs a simple harmonic motion shown.

Curve A in FIGURE 9 shows the curves of movement of the needles andguides shown in FIGURES 6 and 8 of the drawings compounded together. Infact what has been done is to provide the needle with a movement equalin magnitude, but opposite in direction, to that of the guides at anygiven instant. The curve thus shows the movement of the needlerelatively to the guides if the guides were fixed. It will be seen fromthe steep portion of the curve A at the left-hand side of the drawingthat the guides remain practically at the limit of their movement to thebacks, that is on the closed sides of the needle hooks, for someconsiderable time. The movement across the row of needles is thensubstantially horizontal.

It is during the time that'the needles are moving along \'the portion ofthe left-hand-side of the curve A with the guides behindthe needle hooksthat shogging of the guides takes place.

Curve B in FIGURE 9 is similar to curve-A, but shows the movement ,ofthe needlesvrelatively tothe guides when the guides perform the simpleharmonic motion shown in FIGURE 7 of the drawings.

From this it will be seen that the needle passes much more rapidlytowards the guides so that the guidesjhave less clearance from theneedles for a shorter time during which they can make their shoggingmovement.

Since,.however, the; simple harmonic motion is onlyuused whentherearetwo rows of guide eyes, this shortening of the time does not do anyharm.

I claim:

1. In a flat warp knitting machine of the type comprising a row ofreciprocating hooked needles, a needle bar carrying said hooked needles,at least one guide bar, and means pivotally mounting said guide bar forswinging movement to and fro across the row of needles, the combinationof first and second eccentrics, drive means for rotating said eccentricswith the second turning at twice the speed of the first, a cross-head,first and second connecting rods connecting said first and secondeccentrics respectively to said cross-head at points longitudinallyspaced therealong, first mechanical means connected between said needlebar and a point on said cross-head between the connections to saidcross-head of said two connecting rods, and second mechanical meansconnected between said guide bar and a point on said cross-head lying onthe side of the connection of said cross-head to said first connectingrod which is remote from its connection to said second connecting rod.

2. A flat warp knitting machine according to claim 1, in which thedistance between the centers of the connections of said first mechanicalmeans and of said second connecting rod to said cross-head, and thedistance between the centers of the connections of said first mechanicalmeans and of said first connecting rod to said crosshead, aresubstantially in the ratio of two to one.

3. A flat warp knitting machine according to claim 2, in which thedistance between the center of the connections of said first mechanicalmeans and of said first connecting rod to said cross-head, and thedistance between the center of the connections of said second mechanicalmeans and of said first connecting rod to said cross-head, aresubstantially equal to each other; whereby the connections of the twosaid members to the cross-head perform movements which are substantiallythe inverse of each other and are degrees out of phase.

4. A flat warp knitting machine according to claim 1, in which saidmechanical means comprises an arm in which its pivotal connection tosaid cross head is located, and said arm carries an extension towardsaid first connecting rod, and bushes in said extension and in saidfirst connecting rod, said bushes enabling said arm and said firstconnecting rod to be connected together in place of the connectionbetween said arm and said cross-head.

5. In a flat warp knitting machine of the type comprising a row ofreciprocating needles having shanks and hooks with an open and a closedside, a needle bar carrying said needles at the ends of said shanksremote from said hooks and reciprocating said needles in a directionparallel to said shanks, at least one guide bar, and means pivotallymounting said guide bar for swinging movement to and fro across said rowof needles from said closed side to said open side, the combination offirst and second eccentrics, drive means for rotating said eccentricswith the second turning at twice the speed of the first, a crosshead,first and second connecting rods connecting said first and secondeccentrics to said cross-head at points longitudinally spacedtherealong, first mechanical means connected between said needle bar anda point on said I cross headf between the connections. to" saidicross-head of said two connecting rods; andsecondrnechanical meansconnected between said guide bar and: a point on said cross-head lyingon the side of the connection of said 1 cross-head to said firstconnecting rod which is're'mote from its connectiontosaid secondconnecting'rod', said first mechanical means and saidsecond'm'echanical'means being so arranged that when the needle bar isat the limit of itsmov'ement in the direction in which saidhooks leadsaid shanks', said guide bar is at the limit of itsmovement' inanedirection in-wliich it moves from said closed side to said open side ofsaidneedles.

6: A flat warp knitting machineaccording" toclaim 5,

" in which said eccentrics are both at their top dead-centerpositionsat' the same instant, once during each-rotation of said firsteccentric:

' 7. A' flat Warp-knitting machine according to claim 5, iii-which bothsaid guide bar and said needle bar experiencea dWell-whenthey aresubstantially in the positions which they occupy when 'said needle barhas completedits Peel et al. Aug. 4, 1942 Held Jan; 19, 1960

